a. My cousins love making crafts. They're made many useful and nice production.
⇒ "are" bỏ
b, Doing DIY may help develop creation and save money but I'm not so handy that it is a washing of time.
⇒ help → helps
c, She would rather do homework than doing homework.
⇒ do homework → doing housework.
@học_tốt